This invention concerns a thermostat-controlled electric switch for a refrigerator chamber with semi-automatic defrosting.
With thermostats of the prior art, such a switch normally regulates the temperature of a refrigerated chamber by keeping the temperature of the evaporator in the cold-generating system within two predetermined limits T.sub.1 and T.sub.2.
These upper and lower limits, normally below zero Centigrade, can be slightly altered by the user of the refrigerator turning a handle in the desired direction. The difference .DELTA.T between the two selected temperatures remains fixed. Consequently, defrosting can be carried out if at least one of the two limit temperatures is above zero degrees Centrigrade, for a selected position of the handle. This means that the handle has to be turned manually to the defrosting position, then back to its original setting when defrosting is completed.
The switch according to this invention allows one, by pressing on a push-button, to raise the temperature for which the compressor unit of the refrigerator comes into operation, to a temperature T.sub.D (defrosting temperature) above 0.degree. C., during a single operating cycle, the length of which depends on the average working temperature selected for the refrigerator. Return to normal functioning and resetting of the control button are automatic.